Selection of Typical Meteorological Cycles Based on Comparison of Cumulative Distribution Functions of Different Meteorological Indicators and Assignment of Normalized Modeling Research

Liaoning region is selected as the study area, and its meteorological data from 1974 to 2024 are used as the study samples.Based on the four indicators, SPI, SPEI, EDDI and CJDI, the normalized composite drought characteristic indicators were constructed by using the CVine joint function and entropy weighted TOPSIS, so as to explore the drought calendar and drought intensity in the Liaoning region, and to analyze the spatial and temporal evolution of the drought cycle.The results showed that the Kendall and Spearman rank correlation coefficients reached above 0.60 and 0.73, respectively, and therefore, the drought duration and drought intensity were strongly correlated.The normalized composite drought characteristics index had a significant negative correlation association with SPI (P<0.01).The normalized composite drought characteristic index has a significant positive correlation association with SPIE (P<0.05).SPI and SPEI are one of the important reasons to study the spatial distribution and temporal pattern of regional drought.